The most common network filtering programs is iptables. In latest Red Hat Enterprise and other linux based Operating system another firewall is available named as Firewalld . Iptables was the main method for network packet filtering program in earlier or old Red Hat and CentOS versions.

In latest CentOs / RHEL 7 both system based OS, so we will use system related command to enable,disable and stop firewall and iptables.

[/box]

Disable Firewalld :

[box]

Here we are going to disable and stop default firewall firewalld .

# systemctl stop firewalld

# systemctl disable firewalld

In latest version of RHEL / CentOs, both iptables and firewalld can be available for use, then system may have conflict services installed . For prevention of an administrator from accidentally starting a service, a service may be masked.Masking will prevent if the services is started , nothing will happen.

# systemctl mask firewalld

[/box]

Install and Configure Iptables :

[box]

Here we are going to fresh install iptables service, may be in your server it already installed. Please check other wise install through below command.

# yum -y install iptables-services

Create Iptables files :

Run below command for create a blank or null files for iptables.

# touch /etc/sysconfig/iptables

If you use ip6tables services , then run the below command.

# touch /etc/sysconfig/ip6tables

To check and verify service will starts at boot :

# systemctl enable iptables

If you are using ip6tables, please run below command otherwise you can left or skip below command.

# systemctl enable ip6tables

Now lets start the iptables services.

# systemctl start iptables

For ip6tables services, use below command.

# systemctl start ip6tables

Now we have run the iptables services and stop and disable firewalld services.